Pothos is a trailing vine plant that produces attractive glossy leaves in many variegated colors.
In the right conditions, pothos grows prolifically and can live up to ten years indoors. But like many houseplants, pothos can often suffer from root rot. Untreated, root rot is almost always deadly.
Let’s take a look at what causes pothos root rot, how to treat it, and how to prevent it in the first place.
What Causes Pothos Root Rot?
Root rot begins at a plant’s root system. Untreated, the disease will spread until it causes the entire plant to decay.
Pothos can develop root rot from one of two causes: overwatering or fungal infection.
Plants need oxygen to perform respiration. Respiration is the chemical process through which plants produce energy. Overwatering reduces the availability of oxygen in the soil, making it difficult for plants to perform this necessary function.
Waterlogged soil also makes it difficult for roots to absorb water and nutrients. And without oxygen, roots will accumulate toxins, weaken, and eventually die.
Overly moist or waterlogged soil also creates the perfect habitat for soil fungus.
Brown and black leaves typically indicate a pathogenic infection. A few types of pathogens can cause root rot: Phytophthora, Pythium, and Rhizoctonia.
Phytophthora is a water mold. Once the mold has infected the root system, it spreads above the soil to attack the stems and leaves. Pothos suffering from phytophthora root rot may display wilting, yellowing leaves or leaves with brown spots. The stems of infected pothos may develop dark lesions, and roots will turn black or brown.
Pythium is a parasite that causes root rot and stunted growth. The roots will also develop water-soaked cankers. Fungus gnats often transmit pythium.
Rhizoctonia is a fungus that develops in soil and eventually attacks roots. It slows new growth and causes yellow, wilted leaves. It can also cause brown lesions to form on the stems.
Root rot might also be a symptom of southern blight, a fungal disease that occurs in hot, moist environments.
Pathogens spread in a variety of ways.
Potting mix, water, pruning shears, shovels, pots, and other garden equipment can become contaminated.
Planting pothos directly into ground soil (as opposed to pots) increases the risk of exposure to naturally occurring pathogens.
If one of your houseplants develops root rot from a fungal infection, it is best to quarantine that plant until treated. Pathogenic spores can easily spread from hanging plants to the ones below.
Healthy plants can often resist soilborne pathogens. But once weakened, plants become more vulnerable to infection.
Rotted Roots vs. Healthy Pothos Roots
Pothos root rot looks pretty much the same across pothos varieties.
So let’s look at identifying features of root rot. The sooner you identify root rot, the greater your chance of saving the pothos.
- Appearance: white, tan, white tips
- Texture: firm, succulent
- Smell: earthy
- Appearance: brown or black, sometimes with dark lesions
- Texture: sagging, slimy, mushy,
- Smell: decay, rotten egg
Root rot affects more than just pothos roots. To diagnose whether or not your pothos has root rot, look at the leaves.
The leaves on a pothos with root rot will turn yellow and flaccid, eventually dropping off the stem. The leaves can also develop yellow stripes or brown spots.
But leaf yellowing is not in itself an indication of root rot. You will need to consider leaf appearance in conjunction with soil moisture. If the soil remains damp several days after watering and the leaves are yellow, the plant probably has root rot.
Root rot limits the plant’s ability to absorb vital nutrients, water, and oxygen. Nutrient deficiency stunts pothos growth. If your pothos has root rot, it might produce smaller, curling leaves at less frequent intervals creating an overall thinner, leggy appearance.
In some cases, pothos with root rot might have mold develop on the leaves, stem, and topsoil. Moisture-loving pests such as mealy bugs, spider mites, aphids, and whiteflies might also be present.
5 Steps to Treat Pothos Root Rot Like a Pro
It might be tempting to dump rotted pothos onto the compost heap, but this popular houseplant can recover from root rot if you act fast.
The exact treatment varies slightly depending on the cause of the root rot: fungal infection or overwatering.
The simplest course of action is to assume that the root rot has resulted from a fungal infection.
1. Remove pothos from its pot.
Rotted roots are delicate; use care when removing the afflicted pothos from its container. Place the pot on its side, supporting the stem base. Gently tap the container to loosen the soil, then slowly pull out the plant.
If the soil is compacted, use a sterilized knife to separate the soil edges from the pot.
2. Prune the infected areas.
Identify and remove the infected roots (those that are brown, black, mushy, etc.). Sterilize tools between each snip to prevent fungal spores from spreading.
Then cut away dead or decaying foliage (stems and leaves).
3. Remove excess soil.
Gently shake the pothos to remove excess damp and potentially infected soil. If necessary, you can remove additional soil by carefully loosening the roots.
Rinse the roots to remove stubborn soil.
4. Disinfect the roots.
If your pothos root rot has resulted from overwatering, you can skip this step. But since this step can only help your pothos, it’s better to be safe than sorry.
Using Hydrogen Peroxide on Pothos Root Rot
Soak the roots in a mixture of hydrogen peroxide and water – 1 part hydrogen peroxide to 16 parts water.
(Per molecule, hydrogen peroxide has a higher oxygen content than water. Applying hydrogen peroxide to soil causes oxidation. This oxidation will help eliminate bacteria and fungi that cannot survive in aerobic environments.)
Alternatively, you can disinfect the roots using a fungicide such as neem oil or a solution of warm, soapy water.
5. Re-pot the pothos.
Re-pot the pothos into a sterilized pot. Use fresh soil to prevent reinfecting the plant. Let the soil dry out completely before watering.
In cases of extreme root rot, your best option might be to propagate a new pothos plant.
To propagate, identify healthy foliage. Then use sanitized shears to clip a 4-6” stem that hosts at least four leaves.
Place this clipping in a glass of water. Once roots begin to develop, transplant the pothos from water to soil.
Hydroponic Pothos Root Rot in Water
Pothos can grow in water as well as soil. But growing pothos hydroponically increases the risk of root rot.
The good news? It’s much easier to identify root rot on hydroponic pothos because you can see the roots.
Roots begin to rot and turn brown when they don’t get enough oxygen.
If your hydroponic pothos develops root rot, immediately remove the plant from the water.
Prune the infected roots and foliage. Sterilize the container and fill it with fresh water. Soak the trimmed roots in fungicide, then return them to the water.
Change the water frequently or install an air pump to maintain oxygen levels in the water.
Related Article: Will Pothos Plants Destroy My Aquarium? (Answer + Pros & Cons)
Tips to Prevent Pothos Root Rot
Root rot begins beneath the soil surface, making it difficult to identify the infection. Fortunately, you can take a few steps to prevent root rot in pothos.
- Water: Check soil moisture before watering. Pothos positioned in bright light will need water once the top half of the soil has dried. In spaces with less light, the soil should dry completely through the pot before the next water.
- Fertilization: Fertilizer adds salts to the soil. Overfertilizing a pothos will cause its roots to shrivel. A weakened root system makes the plant more vulnerable to root rot and other diseases.
- Appearance: Keep an eye on the foliage. Yellowing foliage + excessively moist soil indicates that the plant has too much water.
- Soil Aeration: If you’ve recently purchased the plant from a garden center, you might need to loosen the soil with your fingers to promote aeration. This aeration will help release excess moisture from the soil.
- Pot Size: If you have a small tabletop plant, increase the pot size by 1-2” diameter every 12-18 months. If you have a larger floor plant, increase the pot size by 2-4” diameter every 18-24 months. Increasing the pot size too quickly could cause the roots to drown; the more soil a pot holds the more water it can hold. Alternatively, pothos can become root-bound if the pot is too small. (A tangle of roots will slow water drainage.
- Pot Material: Plant pothos in a porous clay pot. These pots allow for side evaporation.
- Temperature: Pothos grow best in temperatures between 60-85 F. Soil dries more slowly in low temperatures.
- Drainage: Plant your pothos in well-draining soil. Add perlite, vermiculite, or sand to improve drainage if necessary. Make sure there are drainage holes in the bottom of the pot. And if the pot does have drainage holes, don’t forget to empty the drainage saucer.